The metadata below describe the original scanning. Follow the "All Files: HTTP" link in the "View the book" box to the left to find XML files that contain more metadata about the original images and the derived formats (OCR results, PDF etc.). See also the What is the directory structure for the texts? FAQ for information about file content and naming conventions.
"The ten articles contained in this work were contributed, with one exception, to the North American review, during the years 1911 and 1912. The exception is the seventh--The Panama canal and sea power in the Pacific--which appeared in the Century magazine for June 1911."--Pref